Compression refrigerating apparatus



June 16, 1933. K. 'wmem' 1,399,957

COMPRESSION REFRIGERATING APPARATUS I Filed Aug. v2.7-; 1926 l atentecl June 16, 1931 UNITED s'mrs I i,8 -tt,957

ATENT FFIcE LEONARD KAY WRIGHT, OF ASTORIA, LONG ISLAND CITY, NEW YORK COMPRESSION REFRIGERATING APPARATUS Application filed August 27,

The invention and improvements relate to compression refrigerating machines and apparatus, more particularly apparatus designed for household use, and the chief object is to provide improved apparatus simple in construction and low in cost which may be operated with greater efficiency. To this and other ends the novel features are illustrated and described in the accompanying text and drawings in which: v

Figure l is a diagrammatic illustration of a compression refrigerating system embody-- ing my invention. I Figure 2 is a diagrammatic illustration of a modified form of part of the apparatus shown in Figure l and,

Figures 3 and l respectively are diagrammatic illustrations of two modifications of my improved evaporator unit.

Fig. 1 is a diagrammatical view of a compression refrigerating system, in which A is the compressor, B the condenser, these two aforementioned'being interconnected by the discharge line H, C is the receiver, which acts also as an oil separator, D is the'liquid line which supplies the throttle or expan sion valve E with liquid refrigerant, F being the evaporative section which is placed in the chamber to be cooled and G is the suction line which conducts the gasified refrigerant to the pump or compressor. I is the oil line which supplies the pump with lubricant. In such systems where the lubricant is of greater density than the refrigerant, as for instance, ammonia and oil, ethyl chloride and glycerine, the oil supply line I is so placed that it taps thelowest portion of the receiver and conveys nothing but oil to the compressor, while the liquid refrigerant line D is placed with its open end at a higher elevation, so as to tap the refrigerant from which the oil has settled. Arrows denote the direction'of flow through the various pipes or tubes. I

Rotary compressors require a rather copious amount of lubrication and are usually connected to a vertical discharge line which connects to the top of the condenser. Due to the large amount of lubricant handled the vertical dlscharge line tends to clog and pre'-,

1926. Serial No. 131,944.

rise in the dischargeline is eliminated and co the discharged gas and oil, in leavingthe discharge pipe H, impinge upon the verti cal condenser tube or tubes, which allows the entrained oil to fall to the bottom; the warm oil-freed gas rising to the upper portion of the condenser, which, not having oil films to retard heat transfer, condenses the gas withgreater efficiency. The liquefied refrigerant trickles down the condenser tubes and collects in the receiver C. It is obvious that two thirds of the condensing surface is thus kept'in an oil free condition and throughthe elimination of these oil films enables-the condenser to function with greater efliciency, which permits a reduction in size. This 7 maintenance of two thirds or more of the condenser surface in an oil free condition, conducive to greater heat transfer and a reduction in size, is one of the objects of my invention.

In Fig.2 is shown another method of constructionin which B is the condenser, H being the discharge line which is connected to the condenser tube J, C' is the receiver, D the liquid line and I the oil supply line. A hous ehold refrigerating machine of simplest design would use the first method of construction,.that is the condenser would act also as a reservior or receiver, while the second construction, which uses a separate condenser and a separate receiver, would be used on larger and more complicated machines.

Another object of my invention is to improve the operatingefficiencyof evaporators. 1

Allevaporators in such'systems where the 9 lubricant is of greater density than the refrigerant suffer through oil accumulation,

which affects the efficiency to an extent depending upon the amount of the acumulation 1 the accumulation displacing liquid refrige- 10 rant, while the oil film is spreading itself over the surface of the evaporator impairs heat exchange. In some cases evaporators trap the total charge of oil that was placed in the machine, and may end in the destruction of the compressor, for without lubricant the moving portions score andgrind themselves beyond repair.

In Fig. 3 is shown my improvement applied to an evaporator, the purpose of which is to remove all oil or lubricant accumulations so that at the beginning of each cooling period the evaporator will be in an oil free condition. The liquid line D which supplies the refrigerant to the throttle or expansion valve Eimay. be placed so as to feed the evaporator:

section F from the top, bottom or at any convenient point, but the gas line L, which is connected to the suction line Gr,,must be con nected on, at or near the top of the evaporator section F, so that when the evaporator section is operating in its heat removing capacity nothing; but gaseous refrigerant will be A siphondrawn back to the compressor. tube K.1s placed in the evaporator sec tion, one

endin-closeproximity with the lowestpontionof the'evaporator. section, the other end of the siphon tube being. connected to the sue-- tion-line G.

In operation the following occurs:

When-the compressor has beenoperafiing a sufiiei-ent length of time so that the required coeilness in the refrigerated space is attained the current. is shut off and the compressor stopped; The condenser and receiver, being:

subjectedito the warmth of the atmosphere,

are under a higher presure than the evapora tor! and continue to force liquid refrigerant through; theliquid supply line D, through the expansion valve E, into-the evaporator chamber F. The temperature and pressure difference between the high side and the low sidecauses the evaporator to fill with liquid refrigerant. As soon as the tube K is immersed and becomes filled it will begin to function as a siphon, and begin to unload the evaporator of any oil which had been trapped from the previous refrigerating operation; the oil and liquid refrigerant passing, through the siphon tube K. and draining into the suction line G; When the suction line has filled with oil orliquid. refrigerant the evaporator section will continue to fill until very little gas spaceremains. lVhen the machine is called uponto perform its refrigerating duty and a suction is produced in the return line Gthe siphon tube K. will furtherunload the evaporatorsection oflubricant and liquid refrigerant, which collected in the evaporator. The-evaporator. F being entirely emptied. of

all lubricant is inthe best heat exchanging; conditiomsothat the liquid refrigerant err-- teringjfromthe expansion valve E will evap-.

orate. or boil indirect contact with the evap orator section, unhindered by oil films or through displacement by their accumulation.

The loop in K must be placed so as to be just beneath the gas return opening L, for it is obvious that if the loop was located above the gas line L it would never function as a siphon, due tothe fact that it wouldnever: become filled (with liquid. This gasiline ispreferably placed at the highest point of the evaporator, that is on, at or near the top, so that the loop K-"can be insertedin'the evaporator with the top of the loop touching the inner side of the top'of the evaporator.- By doing so the liquid level is maintained at maximum height, leaving very little gasspace. It is well known in theart; that an e aporator will function best when theinner surfaces are wet. with lid-- uid refrigerant, as the gaseousrefrigerantperforms-verylittle refrigerating duty and" therefore. the gas-space should boas-limitedass-possible.

Fig. 4i shows an evaporator, equipped withthe oil removing siphon tube whichutilizes a cup or: depressionto collect the lubricant. The siphon tube is inserted so that one endis immersed-inithe cup X, the otherL end'of the siphon. tube'beingv connected aspreviously stated, to the suction line G.

While I have illustrated inthe foregoing specification and. the accompanying, drawings certain specific embodiments of my invention, I wish it to be clearly understood that snchillustrations are not to lie-taken as limitations of the scope of my invention, but are merely for'the' purpose of disclosing a single embodiment thereof. I. do not wish to be limited in thcscope or practices of this invention exccptbytheterms of the appended claims.

Having, described my invention and improvements what Iclaim new is:

1-. In a refrigerating apparatus, an evapo rater equipped with a-supply line,,a suction line, and asiphoning tube. so arranged that innorinaloperation a portion of its length is above thesurf'ace of'the liquidrefrigerant; one endoi'gthe siphoning, tube beingin close proX-in'iity with the, lowest portion of the in? side of the evaporator. the other. end of said tube beingconnected to said suction line.

In a refrigerating amaaratus,.anevap orator, a=conduit connected therewith adiacentthe upper portion thereof for supplying. a refrigerantthereto, an outlet conduit connected with said evaporator adjacent itsupper portion and means mounted. in said evaporator for-draining substantially all of the liquid therefrom automatically. when the liquid reaches a predetermined level.

3. In arefrigerating apparatus, an evaporator,a conduit connected tl1erewith.adjacent the upper portion thereof, for, supplying. a refrigerant-thereto, an outlet conduit con nected with said. evaporator adj acent. its upper portion and means nounted insaid.

evaporator for draining liquid therefrom 7 when the liquid reaches a predetermined level, said means comprising a siphon, one

end of which isarranged adjacent the lower portion of said evaporator and the other end of which extends through said evaporator to a point of discharge. I

4:. In a refrigerating apparatus, an evaporator, a conduit connected therewith adjacent the upper portion thereof, for supplying a refrigerant thereto, an outlet conduit connected with said evaporator adjacent its upper portion and means mounted in said evaporator for draining liquid therefrom when the liquid reaches a predetermined level, said means comprising a siphon, one

end of which is arranged adjacent the lower portion of said evaporator and the other end of which communicates with said outlet conduit. I

5, A refrigerating apparatus comprising a source of liquid refrigerant and an evaporator said evaporator having a refrigerant inlet and a refrigerant outlet and a siphon mounted in said evaporator adapted to discharge oil introduced therein,

6. In a refrigerating apparatus an evaporator, a conduit connected therewith adjacent the upper portion thereof, for supplying a refrigerant thereto, an outlet conduit connected with said evaporator adjacent its upper portion and means mounted in said evaporator for draining liquid therefrom when the liquid reaches a predetermined level,'a cup like depression in the lower portion of said evaporator, said means comprising a siphon, one end of which is arranged within said depression and the other end of which extends through said evaporator.

7. In a refrigerating apparatus, an evaporator, a conduit connected therewith adjacent the upper portion thereof, for supplying a refrigerant thereto, an outlet conduit connected with said evaporator adjacent its upper portion and means mounted in said evaporator fordraining liquid therefrom when the liquid reaches a predetermined level, a cup like depression in the lower por tion of said evaporator, said means comprising a siphon, one end of which is arranged within said depression and the other end of which communicates with said outlet conduit.

In testimony that I claim the foregoing as my own, I have hereto affiXed my signature.

LEONARD KAY WRIGHT. 

